Reference voltage circuit

Abstract

The invention discloses a reference voltage circuit. The reference voltage circuit comprises a first-order compensation circuit for producing current irrelevant to first-order temperature, a curvaturecompensation circuit connected with the first-order compensation circuit and used for producing current having high-order temperature characteristics and superposing the current and the current irrelevant to first-order temperature to produce current irrelevant to high-order temperature, and a voltage generating circuit connected with the curvature compensation circuit and used for generating reference voltage according to the current irrelevant to high-order temperature, wherein the curvature compensation circuit comprises a current source and a first audion, the current source and the firstaudion are matched to produce current having high-order temperature characteristics, and the current source is a current source having a zero-temperature coefficient. In this way, high-order temperature compensation can be achieved, a circuit structure is simple and easy to achieve.

Description

technical field [0001] The invention relates to the field of voltage generating circuits, in particular to a reference voltage circuit. Background technique [0002] Most of the semiconductor integrated circuits require an internal reference voltage. In order to keep the reference voltage constant within a certain temperature range, it is often achieved by first-order temperature compensation, and the first-order compensation circuit has a complex structure, or in some In the existing scheme, only the compensation of the first-order temperature coefficient of the reference voltage is completed, and the general temperature coefficient is tens of ppm / °C. In some applications that require higher precision and a small temperature coefficient, this compensation cannot reach Therefore, a second-order or higher-order temperature compensation is proposed. The existing second-order or higher-order temperature compensation circuit has a complex structure and is difficult to implement....

AI Technical Summary

Problems solved by technology

[0002] Most of the semiconductor integrated circuits require an internal reference voltage. In order to keep the reference voltage constant within a certain temperature range, it is often achieved by first-order temperature compensation, and the first-order compensation circuit has a complex structure, or in some In the existing scheme, only the compensation of the first-order temperature coefficient of the reference voltage is completed, and the general temperature coefficient is tens of ppm / °C. In some applications that require higher precision and a small temperature coefficient, this compensation cannot reach Therefore, a second-order or higher-order temperature compensation is proposed. The existing second-order or higher-order temperature compensation circuit has a complex structure and is difficult to implement.

Images